Wednesday, July 31, 2013

Managing Spawl to Produce Sustainable Communities

Can We Have Sustainable Transportation without Making People Drive Less or Give up Suburban Living? (Abstract, Mark Delucchi and Kenneth S. Kurani, Journal of Urban Planning and Development, Jun. 26, 2013)
Today we review an article that addresses the biggest challenge to a carbon free society- sprawl, based on long commutes to widespread communities, fostered by the long era of cheap oil and gas. The proposed solution is to aim at small to mid-sized cities (under 100K) which restricts heavy polluting vehicles to the outer ring of the city and conserves the urban populated centre for low speed, less polluting modes of
 low density homes  

Key Quotes:

car ownership is so desirable that any effort to address sustainability must embrace it, rather than defy it.”

 “what's so pernicious about modern sprawl is not the cars themselves, per se, but their "high kinetic energy" — in simple terms, their size and speed.”

“find a way to dramatically lower the kinetic energy of personal travel while sustaining the advantages of personal, self-directed mobility and access to both urban and suburban living. … create two autonomous and universally accessible travel networks: one for fast-heavy vehicles, the other for low-speed, low-mass, transportation modes, including new designs of motorized vehicles.”

“People would live in small city clusters built around a town center replete with stores, offices, schools, public buildings, and parks. Traveling around town, residents would take the "light" road network. They would walk, bike, or drive tiny cars incapable of exceeded 25 mph. There would be no on-street parking at all. The general idea is to promote interaction and accessibility.”

“Conventional cars would travel the "heavy" road network out of town, mostly to commute elsewhere for work or shop at big box stores confined outside the city limits….Multi-family residential buildings would be situated closer to the center, with lower-density single-family units constructed toward the outer fringe. The towns themselves would be limited to populations of 50,000 to 100,000.”

“if the problems of urban sustainability had an easy answer, we probably would have already found it.”
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Monday, July 29, 2013

Reducing GHG Emissions by Shorter Commutes and More Energy-Efficient Homes

Also discussed here: 21 Percent of Homes Emit 50 Percent of CO2(Julia Whitty, MotherJones, Jun. 27, 2013)

Today we review estimates of CO2 emitted by the two largest sources in a medium-sized Swiss town: emissions from homes and vehicles. While it has long been known that these two sources account globally for 70% of greenhouse gas emissions, this research looks at grouping within the population and found that larger houses (which makes up about a fifth of the total) and drivers with longer commutes accounted for more than 50% of the total. This suggests that a focus on home and vehicle energy efficiency (or on smaller homes and shorter commutes) would produce the most effective results, to the extent that reducing the emissions of these two groups by 50% would reduce the overall total by 25%.

ghg homes emissions
Key Quotes:

“The energy people use to power their homes and drive their lives accounts for more than 70 percent of CO2 emissions”

“on a midsized community, we found a median value of greenhouse gas emissions of 3.12 t CO2 equiv and a mean value of 4.30 t CO2 equiv per capita and year for housing and mobility.”

“Twenty-one percent of the households in the investigated region were responsible for 50% of the total greenhouse gas emissions, meaning that if their emissions could be halved the total emissions of the community would be reduced by 25%.”

”driving factors for large environmental footprints are demands of large living area heated by fossil energy carriers, as well as large demands of motorized private transportation.”
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Friday, July 26, 2013

Do HOT Lanes Reduce Congestion or Raise Revenue (or both)?

Why Are HOT Lanes Struggling to Make Money?(Eric Jaffe, The Atlantic, Jun. 24, 2013)
Also discussed here: Where Are My Cars: SR-167 HOT Lanes -Revenue has fallen far short of expectations(Sightline, Clark Williams-Derry, May 21, 2013)

Today we review an article on how to implement HOT lanes to reduce congestion and raise revenue, a “hot” item in Ontario because of the recent decision to implement them in the Greater Toronto Area (GTA) and, after a year, extend them to the remaining 400 series of highways across Ontario (notably to the Queensway that bisects the City of Ottawa as the 401 bisects the City of Toronto). The author notes that experience in several states in the US show that both the traffic flow and revenue are much less than even the lowest scenario planned. The solution seems to in deciding on prime objective: either to raise revenue or reduce congestion but not both, at east until drivers get used to optimizing their experience with tolls so that they save time at the appropriate price, noting that the dynamic toll amount does not always direct link with congestion levels for drivers deciding whether to use a HOT lane or not.

HOT revenue lanes

Key Quotes:

“Virginia's new HOT lanes on Washington, D.C.'s Beltway lost $11.3 million in their first six weeks, Houston's I-45 and U.S. 59 express lanes haven't covered their costs, and Atlanta's I-85 tolls fell short of the lowest fiscal forecasts.”

"We're selling these things hard — at least the public sector — as congestion relief and revenue generation….These are still a good tool for us, but we need to use that tool better, because we're missing out on some of the opportunities."

“If you can't estimate how many drivers will use a road, then obviously any revenue forecasts are going to miss their mark”

“The price of using the HOT lane, which ranges from 50 cents to $9, updates every five minutes to ensure a speed of 40 m.p.h. But while the formula has been effective for congestion, sometimes saving drivers 12 minutes on a 10-mile stretch of road, it hasn't been tweaked to generate more revenue”

“actual HOT lane revenue in 2012 was about one-third of the “low case” projection that WSDOT made before the lanes were opened.”

“Price as a signal of congestion is rather noisy, It's not perfect."

“They should also enter projects with a clear sense of whether they want their express lane to offer congestion relief or generate revenue — and shift toll formulas accordingly. And they should factor a period of driver adjustment into fiscal forecasts”
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Wednesday, July 24, 2013

How Many Particulates Can Trees Remove from the Air?

Modeled PM2.5 removal by trees in ten U.S. cities and associated health effects(Abstract, David J. Nowaka, Satoshi Hirabayashib, Allison Bodineb, Robert Hoehna, Environmental Pollution, July 2013)

Also discussed here: Urban Trees Remove Fine Particulate Air Pollution, Save Lives(Science Daily, Jun. 19, 2013)

Today we review research into the amount of fine particulate matter [PM 2.5] removed from the air by urban trees and what this means in terms of economic benefit from human health cost savings. Results from 10 US cities indicate that trees improved air quality by 0.05 to0.24% which appears small but when applied to a city as large as New York translates into 7.6 premature deaths avoided or delayed and over $60 M saved.

Centre ville d'Atlanta, Géorgie, Etats-Unis
Centre ville d'Atlanta, Géorgie, Etats-Unis (Photo credit: Wikipedia)

Key Quotes:
"This research clearly illustrates that America's urban forests are critical capital investments helping produce clear air and water; reduce energy costs; and, making cities more livable. Simply put, our urban forests improve people's lives."

“estimated how much fine particulate matter is removed by trees in 10 cities, their impact on PM2.5 concentrations and associated values and impacts on human health”

"Trees can make cities healthier…While we need more research to generate better estimates, this study suggests that trees are an effective tool in reducing air pollution and creating healthier urban environments."

“Mortality reductions were typically around 1 person yr−1 per city, but were as high as 7.6 people yr−1 in New York City. Average annual percent air quality improvement ranged between 0.05% in San Francisco and 0.24% in Atlanta”

“The total amount of PM2.5 removed annually by trees varied from 4.7 metric tons in Syracuse to 64.5 metric tons in Atlanta, with annual values varying from $1.1 million in Syracuse to $60.1 million in New York City. Most of these values were dominated by the effects of reducing human mortality; the average value per reduced death was $7.8 million”

Reduction in human mortality ranged from one person per 365,000 people in Atlanta to one person per 1.35 million people in San Francisco.”
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Monday, July 22, 2013

Limiting Unsustainable Growth by Using Economic Tools

Monetary and Fiscal Policies for a Finite Planet(15 page pdf, Joshua Farley, Matthew Burke, Gary Flomenhoft, Brian Kelly, D. Forrest Murray, Stephen Posner, Matthew Putnam, Adam Scanlan and Aaron Witham, Sustainability, Jun. 20, 2013)

Today we review a very thoughtful article that examines fiscal and monetary measures that would transform unstable boom or bust economic systems that affect both the economic and ecological worlds into steady-state economies. The authors point out the much greater complexity of the laws of ecology and the need to constrain economic measures that create the debt and ecological crises seen in many countries today. In short, “Tax What We Take, Not What We Make”.

Economic growth
Key Quotes:

“The laws of ecology impose even tighter constraints on economic activity than the laws of physics….when ecosystem structure is removed and waste returned… ecosystem functions are affected”
“two ecological requirements for a steady-state economy:
  • humans cannot degrade or deplete any element of ecosystem … faster than it can restore itself without eventually crossing some threshold beyond which that component of the structure is gone
  • humans cannot emit waste into any finite system at rates greater than it is absorbed or, else, waste stocks will accumulate, eventually harming humans and/or the ecosystem.”
“Modern economies use fiat currencies, which are not backed by any physical commodity.…. backed largely by the taxation power of the government”

“Essential public goods and services for a SSE[steady-state economy] include health and family services, food security, public utilities and banking systems, education, media, arts and ecosystem conservation and restoration.”

“In the area of fiscal policy, we recommend a change from taxing value added to taxing throughput, including depletion, land use and pollution….Tax What We Take, Not What We Make”

“Only a crisis—actual or perceived—produces real change. When that crisis occurs, the actions that are taken depend on the ideas lying around….”

Public credit money could provide a counter-cyclical feedback loop to economic cycles, in addition to supporting adequate investment in critical public goods, without increasing debt levels.”
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Friday, July 19, 2013

Are there Links between Autism in Children and Exposure to Air Pollution?

Perinatal Air Pollutant Exposures and Autism Spectrum Disorder in the Children of Nurses’ Health Study II Participants(31 page pdf, Andrea L. Roberts, Kristen Lyall, Jaime E. Hart, Francine Laden, Allan C. Just , Jennifer F. Bobb, Karestan C. Koenen, Alberto Ascherio and Marc G. Weisskopf, Environmental Health Perspectives, Jun. 18, 2013)  

Also discussed here: Autism, Air Pollution Link Confirmed By First National Study(Catherine Pearson, The Huffington Post, Jun. 18, 2013)  

And here: Risk of autism is up to 50% higher in children exposed to traffic fumes and air pollution(Nicola Rowe, The Daily Mail, Jun. 18, 2013)

Today we review a paper that looks at the development of autism in children following exposure of their mothers to air pollution during pregnancy. Autism, found in 1 in 50 school age children, is significantly associated with exposure to 26 out of 180 pollutants or neurotoxins, of which diesel and mercury are twice as likely to produce this disorder. Boys are five times more likely to develop autism than girls.

pregnant woman

Key Quotes:

“Autism is found in 1 in 54 boys, compared to 1 in 252 girls…1 in 50 School-Age Children in the U.S. has an Autism Spectrum Disorder…20 to 30 Percent Of Children with an ASD Develop Epilepsy”

“Our findings raise concerns since, depending on the pollutant, 20 per cent to 60 per cent of the women in our study lived in areas where risk of autism was elevated”

“Twenty-six of 180 pollutants had a significant association between exposure and autism rates…Since so many [pollutants] were linked to higher autism rates, we can’t tell from the study which ones might be the causes.. these things [pollutants] are neurotoxins and they can pass from mother to the fetus while it’s still developing…some of these chemicals can cause genetic mutations – the type associated with autism.”

"Women who were exposed to the highest levels of diesel or mercury in the air were twice as likely to have a child with autism than women who lived in the cleanest parts of the sample,"

"All of the chemicals studied are known neurotoxins…They are also known to pass from mother to baby while a woman is pregnant. It's very plausible that the 'stuff' the mother is taking in through the air is affecting her baby's brain development."

"Our data is not good enough to know which thing in the air might actually be causing this [link], if it even is something in the air that is increasing the risk of autism…It might be that it's actually diesel that's [behind] the problem. We are skeptical about the possibility of mercury being causal in this way, through the air."

 “We observed significant positive linear trends between pollutant concentration and ASD for diesel particulate matter, lead, manganese, methylene chloride, mercury, and nickel”

 “Mother’s residential proximity to a major freeway during pregnancy has also been associated with ASD in a study including 304 ASD cases “
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Wednesday, July 17, 2013

HOV to HOT lanes - a first step to More Effective Congestion Pricing?

Gaining Public Support for Freeway Congestion Pricing(25 page pdf, Robert Poole, Reason Foundation, April 2012)

Today we review a report which proposes a more effective approach to relieving highway traffic congestion and to generate more revenue for highway improvements than the unpopular flat tolls. The recent conversion of high occupancy vehicle (HOV) lanes to high occupancy toll lanes (HOT) in the USA and some Canadian provinces (notably as proposed for 400 series highways in the Greater Toronto Area in the 2013 Ontario budget) could herald a more sophisticated 3-stream system that would both improve traffic flow of traffic and recover more revenue as warranted from vehicles that cause the most damage to highways (trucks). Most important is the step by step approach to gain popular favour to congestion pricing in general.

hot lanes
Key Quotes:  

Federal efforts dating back to the 1970s to induce one or more urban areas to price its freeways have all been unsuccessful.. this evolutionary, bottom-up model of freeway pricing should be seriously considered”

“with over 91% of households owning motor vehicles,8 in most states the motorist population is practically synonymous with the voting population…. many (though not all) tolling and pricing proposals garner popular opposition because they don’t add value to the roadway”

 “Charging the same price to all users during rush hour ignores the huge variability in people’s value of time (and their value of the reliability of trip times).. A uniform price applied to all rush-hour travelers will overcharge many and undercharge others”

“The current trends toward converting HOV lanes to HOT lanes and adding new priced express lanes are the potential first steps away from the conventional model of pricing. The second step should develop complete networks of priced lanes, aimed deliberately at those trips with the highest value on any particular day.”

“if congestion is still a problem on the remaining GP lanes, the benefits of pricing on the (by now) larger system of premium lanes will be obvious to a larger fraction of the population…. support for implementing modest peak pricing on the remaining GP lanes, flattening the peaks and shifting some trips to alternate modes.”

“a three-tiered system of lanes and pricing, as follows:
  • Premium lanes, offering guaranteed trip times by means of demand-based pricing;
  • Regular lanes, using modest peak-period tolls to spread the peak load to shoulder periods;
  • Truck-only lanes, designed and priced for heavy trucks.”
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